import pandas as pd
import numpy as np
data = pd.DataFrame(np.arange(16).reshape((4,4)),
    index=['Ohio','Colorado','Utah','New York'],
    columns=['one','two','three','four'])
#>>> data
#                     one  two  three  four
#          Ohio        0    1      2     3
#	  Colorado    4    5      6     7
#	  Utah        8    9     10    11
#	  New York   12   13     14    15

#要删除'two', 'four'所在的列，该如何操作？
def action():
    return None

def test_action():
    res = action()
    assert (res.columns == ['one', 'three']).all()
